Driveline coupling with safety interlock mechanism latchable in the open

Abstract

A coupling assembly including a lock latchable in the unlocked position particularly for connecting a universal shaft with a power takeoff shaft in agricultural implements, wherein a coupling sleeve on the universal shaft may be slipped into torque transmitting engagement onto a power takeoff shaft and held in the locked position by locking members engaging within an annular groove of the power takeoff shaft. A lock ring holds the locking members in the locked position and when it is desired to release the coupling, a gripping sleeve is moved so as to disengage the lock ring from the locking members to enable disengagement of the locking members from the annular groove in the power takeoff shaft. A resilient spring washer having an axial slit is provided with a first and a second conical face on opposed sides thereof, with the first conical face engaging a first complementary conical face on the gripping sleeve so as to drive the spring washer against a second complementary conical face on the coupling sleeve to radially expand the spring washer when the assembly is to be brought into the unlocked position by movement of the gripping sleeve. The spring washer is formed with an inner cylindrical bore which engages a cylindrical seating face on the coupling sleeve to maintain the coupling assembly latched in the unlocked position.